Electric Cooling Blanket

Here is a cool suit. I suppose it could be done in a blanket as well...

http://www.saferacer.com/auto-racing-underwear/cool-suit/?cat=56&tagarray=29

Hello enolaable

The type of suits as shown in Steve S. hyperlink above, rely on cooled liquid being pumped around pipes embedded into the suit.

Am I correct in assuming that you are hoping to make/locate a suit or fabric construction which does not rely on any cooling fluid, just electrical cooling.

If so, the design of such has so far, proved impractical.

There is the principle of the "Reverse Peltier Effect", where if power is applied to juntions of diissimilar metals - in one polarity of the applied Voltage, the bimetal junction heats up, while in the reverse polarity of applied Voltage, the bimetal junction cools.

The main problem is that the removed heat has to be continually shifted somewhere else, and this has, so far, proved impractical, in a fabric or suit type of situation.

Lear more about the Peltier/Seebeck Effects right here: http://www.sciencebuddies.org/science-fair-projects/project_ideas/Elec_p031.shtml

Trust that helps you.

Kind Regards....

Thank you for your response. Based on my very limited knowledge of engineering, physics, and chemistry, I believe your response means "It can't be done." I am very sorry to hear that. Will you answer another question for me? I looked at the Chillow Pillow and found it only stays cool for about 20 minutes. Do you know of anything like that but that stays cooler for a longer period of time?

Yes ice cold water

Yes there is my dear.....well sorta ....it is an electric heating/cooling pad with remote control....it is expensive but the reviews are great!

Go to chilipad.com...Be Blessed.....Fayae

Could the following be done? Very thin piping as PVC about the diameter of refrigerator cooling system, be put in a blanket style material that would keep someone cool enough to sleep comfortably? Something like the suit Steve S described but would be long lasting?

Intriguing? Please would you state the application?

For example: does it have to be a "blanket"?

And how long do you need it to work?
i.e. one hour? Eight hours? Or more?

Can it be connected to a "supply" i.e. mains,
batteries, other? Or does it need to be self sustaining?

To think on it, as an interesting project, criteria is needed.

jt.

Thank you for answering. After I wrote I checked the internet for cooling blanket instead of electric cooling blanket and found several entries. What I was thinking, like a blanket that is temperature controled ( a person could turn it on or off or higher or lower). Based on what I read on the internet, very thin pvc (like refrigerator, ice maker, or freezer) with water that can continue to run through the pvc, all night, with a motor, like a fish tank motor someone said, but that keeps the water cool.

It doesn't have to be a blanket, just some cover to make sleeping more comfortable in summer.

They have something like it for cars, something like it for the medical profession and patient care, but nothing in the unspecialized world at affordable "household" prices.

I was thinking of the old style "dairy" store
where (whatever) is kept cool by evaporation.

If the material is chosen that can be soaked,
e.g. by gravity fed water, such that it evaporates
it will cool the interior by several degrees.

This would require no power supply, and was very
effective in the old days to keep milk and butter cool.
(old worlde fridge)

I am sure the principle could be applied effectively.

Hope this helps, jt.

(I love these sort of problems, and how they over
came them years ago, without any of our facilities.)

I have an electric cool box which I use in the car, this has a peltier style cooler in the lid to keep the contents of the box chilly. I recall that the box only cost me about £20, perhaps something like that could be adapted to cool a blanket or mattress as suggested in previous posts?

Good answer Sparky.

milo

I have never used a water bed, but I believe that they transmit a cool thermal sensation, and that in winter the user must install a heater within the water to avoid being uncomfortably cold. It would be relatively simple to cool the water within the mattress by circulating the water through a small heat exchanger which could take several forms.

Thank you for responding. I am looking for something portable. That can be used on any bed or sleeping place.

If the "water-bed" mattress was thinner, and only contained an inch of water, It could be filled when needed, emptied when finished. Thin flexible tubing connected to a low volume, low noise pump, and a two to three gallon reservoir to transfer the heat from the mattress to the reservoir. The reservoir would radiate the heat to the air, (not to close to the mattress) or th the ground surface. If the reservoir had a hinged cover, the thin mattress and pump could be stored inside the reservoir when not needed. The low volume of water would allow dumping the reservoir first, then the mattress into the reservoir and dumped again. I think it could be workable. Comments?

A Peltier device may be desirable. Simply connecting it to a DC voltage will cause one side to cool, while the other side warms. The effectiveness of the pump at moving the heat away from the cold side is totally dependent upon the amount of current provided and how well the heat from the hot side can be removed. Expect 5% eff.

Thermoelectric cooling, according to my knowledge in physics,relies on the very abrupt change in the density of electronic states near the fermi level,which leads to the transport of heat,and,today,can be achieved only with the semiconductor bismuth telluride.
Recently,a foreign company,which I do not remind but certainly advertises on the net, succeeded in making thick film bismuth telluride.
So,although this compound is very brittle,it should be possible to manage some sort of thick film deposition on a flexible belt,to achieve a cooler belt.
Find and ask that company,perhaps from Eastern countries

anitoff,France.

Don't forget the dew point. You may end up in a puddle. Is your climate dry or humid?

Thank you for responding

dry climate -- Nevada

Enola Able

One reason radiant cooling has not taken off as dramatically as radiant heating is the dew point control required to keep from condensation forming at the cooling surface.

If swamp (evaporative) coolers are in wide use in your area perhaps you could use a blanket that wicks water and a fan.

Ha Ha..! That's sound good idea too. I don't know.! Probably by adapting one of those air mattress pump with a good tygoon hoses blowing air thruw like a sandwiched made consisting of two players of some good breateable material and having some like silica pellets revolving around between these sandwiched players or layers inside will be absorbing the extra heat out of the body causing some cool down feeling after couples of minutes there. I don't know.. Dont bring it to the bank yet I'm just brainstorming here a little with the idea...Heehehe.. But Who Know's ?

Any how like I said having some air motion combined with some good breateable absorbant in the media will help out to cooling down definetly, too bad I don't know about CAD thing, never had the chance to make it out. Alrigth Buddy's "keep it cool" and good day now.

Allgood-Brilliant...

MC

thank you for responding. If you come up with something, please let me know enola able

Think bob c is on to something that I was thinking of too, but perhaps the circulator may not be necessary.

I read that someone once fell asleep on a water bed in the summer and they got hypothermic (their body got too cold).

So that made me think: Why not have a thin water bed effect like a beach air mattress or camping mattress filled with water partially. The water would act like a heat sink and as long as the temperature of the air is less than your body, then your body heat would be pulled away by conduction. The tricky part is not sinking away too much heat. Just wear warmer sleeping clothes might do the trick and no electric might be needed at all perhaps.

To test my theory, I went to a waterbed FAQ site and found info indented below that seems to support my point. Of course you could use a waterbed heater to get the water to the perfect temperature. And if you are only using a 1 inch "thin" waterbed made from an air mattress, then heating the water would not cost as much as a real waterbed. Here is the waterbed info I found that supports my point.

• 41. Can I switch the heating off in the summer?
• No. The room temperature even in the summer is not usually sufficient to keep the water in your waterbed up to temperature. Your waterbed heating, however, will only come on very occasionally in the summer and so will use far less electricity. By setting the temperature a few degrees lower, you can make a waterbed very pleasantly cool on a hot night. A water temperature of 25 ºC should be considered the minimum.

Here is a follow up to my reply above:

I found a company that makes untraditional mattress topper waterbed that is very thin. http://www.waterbed-pillow-cushion.com/water-mattress-faq.html

In it they say that:

• The traditional waterbed which contains large amount of water (up to 1 ton or 1,000 liters of water), can get extremely cold at night even in a tropical country or during the summer. A water bed heater is needed to keep the traditional waterbed warm so that it is comfortable to sleep on.
  
  
  Unlike the traditional waterbed, the Healthplus Water Mattress requires only about 20 to 80 liters of water. With so little water, you don't need a heater.
• 
  If the Healthplus water mattress gets a little too cold, all you'll need is to add extra mattress pad or a quilt to keep it warm. If a layer of mattress pad is insufficient, add 2 or more layers to it until you feel cosy sleeping on it.
  
  When you're using the Healthplus water mattress under room temperature or in a tropical country, usually no more than a layer of mattress pad is needed to be able to sleep comfortably, not too cold and not too warm.
  
  

also in addition to my GUEST comments above, YES they do make a cooling blanket called Chilipad that uses but it is very expensive.

http://www.amazon.com/ChiliPad-Mattress-Topper-Single-CP103/dp/B000VG806O/ref=pd_bbs_4/002-1971277-4806454?ie=UTF8&s=home-garden&qid=1212918051&sr=8-4

Another product is that is less expensive Cool-or-Heat-Sleep-Pad

http://www.amazon.com/Cool-or-Heat-Sleep-Pad/dp/B000RZYP3G/ref=pd_sbs_hg_title_1/002-1971277-4806454

Someone else makes fans that blow air between your sheets from your feet area.

Waooouuh! I'll go for the 'Chilly Pad' thing which does make a plenty of sense absolutetly. This will allow less load on the A/C Unit I'll Bet. Good Deal!

NiceData,

MC

Hello Guest,

The real problem with waterbeds, is that the temperature of water in the bladder is not easily and quickly changed.

We had one for several years, and never had a proper sleep, because once a person is asleep, the body's natural thermostat is switched down slightly.

In a climate with no sudden changes, and in winter, a waterbed may be OK.

What often happens is that the body's natural temperature control mechanism fights against the warming/cooling water, and thus the side of the body against the water bladder, is either too cold or too hot, thus leading to turning over frequently, and a disturbed night.

Kind Regards....

I have been sleeping on my waterbed for 18 years now. We have overcome the mattress temperature concerns by putting a comforter over the waterbed mattress. The additional insulation of the comforter takes the temperature issue out of the waterbed mattress. I live in a house that is kept at 72 to 74 degrees by air conditioning year round. We have pulled the plug on the mattress heater years ago. The only time we plug it in, is the few days that it is cold at night, and use that in place of trying to heat the whole house during the the night. I am still on the original mattress, and worry about finding a replacement as they are not as easy to find as in years past. Did you give up on the waterbed? If not try the comforter.